Screw-thread-cutting machine



(No Model.) 2Sheets-Sheet 1. H. 8B H. L. AMENT. SCREW THREAD CUTTINGMACHINE.

"No; 454,197. Patented June 16,1891.

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(No Model.) 2 Sheets-Sheet 2.

E. & H. L. AMENT. SCREW THREAD CUTTING MACHINE.

No. 454,197. Patented June 16,1891.

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\\\ Xx\ms%s\ \xwmfiwex UNITED STATES PATENT OFFICE.

ELZIE AMENT AND HERBERT L. vAMENT, OF ROGERS PARK, ILLINOIS.

SCREW -THR EAD-CUTTING MACHINE.

SPECIFICATION forming part of Letters Patent No. 454,197, dated June 16,1891. Application filed February 25, 1890. $erial No. 841,765. (Nomodel.)

To all whom it may concern:

'Be it known that we, ELZIE AMENT and HERBERT LfAMENT, citizens of theUnited States, residing at Rogers Park, in the county of Cook and Stateof Illinois, have invented certain new and useful Improvements inScrew-Thread- Cutting Machines, of which the following is aspecification.

Our improvements relate to rapidly-revolving devices driven bysteam-power, not to such as perform a certain number of revolutionsforward in cutting the thread and then the same number of revolutionsbackward to discharge the bolt, but to such as revolve continuouslyforward and in which the discharge of thebolt is procured byan automaticopening of the die and the bolt instantaneously withdrawn.

The die in common use is usually made of two or more pieces, each piecebeing separately guided by one or more pairs of faces perpendicular tothe plane of the axis of the die. They are produced at great cost. Smalldust or chips are carried by centrifugal force into the broad andclosely-fitting bearings, obstructing their action, and the manyprojections of the large revolving head make the attendants proximitythereto dangerous. They are also bulky, unwieldy, and heavy, andadapted, usually, only to machines especially made for the purpose.

The objects of our improvements are, first, to overcome th edifficulties above enum erated; second, to provide a tubular die carriedin a tubular stock revolving continuously forward to adapt the jawsthereof to be opened and closed to release the bolt and to providesuitable means of opening and closing them and of keeping them open whenopen and keeping them closed when closed, and, third, to furnish asuitable means for taking up the wear and,

also render the die slightly adjustable as to size. WVe attain theseobjects by the 1nechanism illustrated in the accompanying drawings, inwhich Figure 1 is a plan view of the machine with the parts appliedtogether for use. Fig. 2 is a front end View. Fig. 3 is a rear end View.Fig. 4 is a front side view, and Fig. 5 is a rear side View, of adetached portion. Fig. 6 1s a central vertical longitudinal section ofFig. 4. Fig. 7 is an exact duplicate of Fig. 6, except that the lattershows the relations of parts with the die closed, while the former showsthe relations of same with the die open. Fig. 8 is a side View of thetubular die by itself. Fig. 9 is a vertical section of the collar andlever shown in Fig. 4:, except that a single screw is employed in theplace of two in the collar, and the lever, by means of hooks, has abearing upon both sides of the collar, and by means of which the levermay upon occasion be employed to open the die as well as to close it.Fig. 10 is a central vertical longitudinal section; and Fig. 11 is anend view of certain of the features of Fig. 6, but differently applied,and also an additional feature, all of which will be more particularlyreferred to hereinafter.

Similar letters of reference indicate like parts in all the drawings.

Although our-improvements are equally applicable to lathes and to screwand bolt inachines generally, they are applied in Fig. 1 to aspeed-lathe, in which A is the bed, A the headstock, and A" thefoot-stock. B is the cone-pulley, B the spindle, B the spindle-socket,and b the socket set-screw. C is the foot-stock lever, 0' its spindle, Cthe spindle-socket, and c the socket set-screw. The lever O is pivotedin the rear end of the spindle C, and the farther end linked to an armof the foot-stock, as represented. One end of the tube D is reduced andsecured in this case in the socket B, and has upon one end of the largerportion an annular groove upon which is secured the box E, the formerbeing allowed to revolve freely in the latter. The lever F, having anoblong aperture through which passes the tube D, is pivoted at thefarther end to an arm of the said box E, and is held in a horizontalposition by a leg E, standing upon the lathe-bed, the upper end of whichis hinged to the said box in front and firmly secured in position by theclamp-screw E. The hinge permits the leg to be folded up parallel withthe handle of the lever, and also to adapt it to lathes of differentswing and width of bed, provided the leg be long enough to pass beyondand rest upon the corner of the bed. The spring F is carried upon a rod,one end of which is set firmly in the box E and the other end projectedthrough a slot in the lever F, as shown,

and which spring is adapted to throw the lever to the right and toalways keep it at thatlimit of its movement when not in use. The lever Fhas two cams f f formed upon the left-hand side, one above and one belowthe tube D, adapted to strike the movable collar G at two oppositepoints. The collar G carries the threaded part of two screws 9 g, eachof which projects through a longitudinal slot (Z d in the tube D, uponopposite sides thereof, and thence into holes h h in the rear part ofthe die H. Said holes are open in this instance upon one side, and whichopening of each turns at a right angle and is cut through to the rearend of the die, as shown in Fig. 8. By virtue of the outlets turned thusat a right angle the die by a slight turn in the stock is in a positionto be withdrawn and by reverse movement returned without removing thescrews or screw, as in Fig. 9, it but one be employed.

The tubular die ll is of one piece. The exterior of the rear end islarge enough to fill the tube D at a movable fit, and the exterior ofthe front end is formed with two conical faces I J, facing backward, theformer at an angle of about forty-five degrees and the latter at only aslight angle-so slight that it is nearly a cylindrical face. Theexterior of the middle portion is turned down small enough to allow thejaws to open sufficiently to release the bolt, as shown in Fig. 7. Themiddle and rear portions of the interior are bored out large enough tobe below the plane of the teeth formed upon the interior of the frontend and allow also some space for chips. The stock of the middle portionshould also be left the proper thickness for springs for the same whenthe tube shall have been divided by incisions h h it into jaws. The jawsare finally spread and tempered, the spring portion being given a springtemper and the toothed portion a die temper. The preferable process isto cut the incisions, spread the jaws, temper the spring portion, andfinally tap and temper the toothed portion; also, the preferable form ofspring and jaw is a tube of larger external diameter and a deep scallopfor the spring next to the plunger-head, and which, being in use insplit jaws for various purposes, need not be furtherillustrated in thisconnection. The outer end of the tube D is counterbored and thecounterbore refilled by a screw-shell or bushing M, a portion of each ofwhich is threaded. The unthreaded portion of the tube carries one ormore set-screws m m, which seize upon the unthreaded portion of thebushin This bushing receives the wear which would otherwise come uponthe tube D, and is adapted, by means of a wrench fitted to holes m m, tobe turned in or out upon the slightly-inclined face J, Fig. 8, for thepurpose of taking up the wear and also for the purpose of rendering thedie slightly adjustable as to size. Turning the screw-shell M in and outvirtually shortens and lengthens the tube relative to the die.

In Fig. 10 the relations of the tube and die are in certain respectsreversed. The adj usting-screw and bushing are separate. Theadjusting-screw is applied to the die. The slots (1 (Z are cut in thedie. The screws 9 g are secured in the tube and do not move with thedie. The relations of certain other parts are also reversible; but theprinciplcsboth of those shown and those not shown are preferably appliedin Figs. 1 and 6.

In Fig. (5 the die is driven by the screws or pins 9 g, projectedintothe plunger-head II but in Fig. 1O.tl1ey are assisted by screws orpins (1 d d, projected between the jaws of the die-head, and whichobviate the necessity of proportionately strong springs H" in a largedie.

The operation of the machine is substantially as follows: The machine,as represented. in full lines in Fi 1, is in readiness to pro cced tothread a bolt. The attendant, by means of the lever C, introduces theend of the bolt 0 into the rapidly-revolving die II, which readilycatches on and cuts an addt tional thread at each revolution. The boltthereby continues to feed into the die until the stop or shoulder Creaches the footstock, at which juncture (see Fig. 6) the bolt ceases tofeed farther, and the die then begins to feed onto the bolt andcontinues so to do until the parts I J are drawn out of the tube farenough to allow the spring of the jaws to open the die and release thebolt, as shown in Fig. 7. The attendant then. by a backward movement ofthe lever C quickly withdraws the bolt, removes it from the socket, andinserts another, and having by means of the lever F, through the mediumof the cams f f, collar G, and screws g g, thrown the die back into thetube, thereby closing it, is in readiness to proceed as before.

It will be observed that the conical face I closes the die, but thelat-ter is held closed solely by the cylindrical face J; that themovement of the die in being opened and closed is strictly alongitudinal one relative to the tube D; that the device has anunobstructed central space which may be utilized in threading screws orrods of unusual length, and that the device may be used while inrevolution, reciprocation, revolution and re ciprocation combined, or inaxial and reciprocal silence.

Having now fully described our invention, what we claim, and desire tosecure by Letters Patent, is-

1. In a thread-cutting device, a stock-tube carrying a tubularthreading-die the jaws of which are opened by a reciprocation of the dieforward and spring of jaws and held open by spring of jaws and closed.by a reciprocation of the die backward and an inclined face of jaw andheld closed by a cylindrical or otherwise slightly-inclined face of jawand portion of tube surrounding same, substanti ally as and for thepurpose set forth.

2. In a thread cutting device, a tubular stock carrying a tubularthreading-die, one end of the latter being divided by longitudinalincisions into spring-jaws, and the automatic reciprocation of the dieforward produced by the feeding of the die onto the1ongitudinally-silenced bolt, substantially as and for the purpose setforth. 1

3. In a threadcutting device, a tubular stock carrying a tubular die ofone piece, a portion thereof being divided longitudinally intospring-jaws, and the reciprocation of the die backward produced by meansof a lever, collar, and screws, substantially as and for the purpose setforth.

4. In a thread-cutting device, the combination of a stock-tube with atubular die longitudinally guided therein, each jaw thereof having aspring and carn face and the die reciprocated backward by means of alever adapted to be shifted by the attendant, substantially as and forthe purpose set forth.

5. In a thread-cutting device, a tubular die having a plunger-headunited by springs to the jaws of a die-head, the exterior of saiddie-head being formed with one conical and one cylindrical face, thesaid springs being adapted to open the jaws and to hold them open, andthe said conical face to close the jaws and the said cylindrical face tohold them closed, substantially as and for the purpose set forth.

6. In a thread-cutting device, a stock tube or barrel carrying a tubulardie, the plungerhead of which is united by springs to the jaws of thedie-head, the exterior of the die-head also being formed with oneconical and one cylindrical or otherwise slightly-inclined face, thelatter in conjunction with an adjustingscrew adapted to take up the wearand to adjust the die slightly as to size, substantially as and for thepurpose set forth.

7. In a thread-cutting device, the combination of the tubular stock D,tubular die H, two or more spring-jaws H H, conical face I, andcylindrical face J, substantially as and for the purpose set forth.

8. In a thread-cutting device, the combination of the tubular stock D,tubular die H, two or more spring-jaws H H", conical face I, cylindricalor otherwise slightly-inclined face J, bolt 0, the latter as one of themeans employed in the extraction of the die, and stops O, substantiallyas and for the purpose set forth. 4

9. In a thread-cutting device, the combination of the tubular stock D,tubular die H, spring-jaws H H", inclined faces I J, lever F, collar G,screws g g, and slots (1 d, substantially as and for the purpose setforth.

10. In a thread-cutting device, the combination of the tubular stock D,tubular die H, spring-jaws H H", inclined faces I J, and combinedadjusting-screw and bushing M, substantially as and for the purpose setforth.

11. In a thread-cutting device, the combination of the tubular stock D,tubular die H, spring-jaws H H, inclined faces I and J, andadjustingscrew M, substantially as and for the purpose set forth.

12. In a thread cutting device, the combination of the tubular stock D,lever F, bar E, and support E, substantially as and for the purpose setforth.

13. In a thread-cuttin g device,the combinationof the stock tube orbarrel D, plungerhead H springs H, die-jaws H, and the inclined faces Iand J, substantially as and for the purpose set forth.

14. In a thread-cutting device, the combination of the tube D, tubulardie H, slots cl d, and pins or screws g g, substantially as and for thepurpose set forth.

15. In thread-cutting devices, the combination, in a tubular die, of theplunger-head H springs I-I", jaw-head H, inclined faces I J, and holes h71, having outlets, substantially as and for the purpose set forth.

16. In a thread-cutting device, the combination of the stock-tube D,tubular die H, springjaws H H, inclined faces I J, and lever F,substantially as and for the purpose set forth.

17. In a thread-cutting device, the combination of the tubular stock D,tubular die H, spring-jaws H H", inclined faces I J, and driving screwsor pins d (1 d, substantially as and for the purpose set forth.

18. In a thread-cutting device, the combination of the tubular spindleB, tubular stock D, and tubular die H, substantially as and for thepurpose set forth.

ELZIE AMENT. HERBERT L. AMENT. Witnesses:

W. O. CORLIEs, S. E. AMENT.

